In the past, reference voltage generation circuits have been used as circuits for generating a reference voltage in circuits of AD converters, DA converters, op-amps, and regulators. These reference voltage generation circuits are generally known for outputting a reference voltage by referring to the silicon bandgap energy created by combining a bipolar transistor element or diode element with resistance. With such a reference voltage generation circuit, however, because an element other than a MOSFET is needed when it is configured on a Large Scale Integrated (LSI) circuit, the number of steps in the production process increases, and therefore operational matching tends to become very difficult. In addition, there arises a problem that power consumption tends to be relatively large, and the chip surface area must be increased to assure high resistance even in cases of operation at a low current.
To overcome these problems Non-patent Document 1 below has proposed a reference voltage generation circuit constructed only from MOSFETs without using a bipolar element and resistor element. This reference voltage generation circuit is one that generates a reference voltage by referring to the threshold voltage in the MOSFETs at the absolute zero temperature. More specifically, the circuit comprises a MOSFET that operates in the strong inversion-linear region in place of resistance, and also a MOSFET that operates in the strong inversion-saturation region, which generates the bias voltage of that MOSFET. The scaling in reference to the thermal voltage by the β multiplier referenced self-biasing circuit, and the equalized currents flowing through each current path of the circuit allow the MOSFET operating in the strong inversion-linear region to add the threshold voltage and the scaled voltage by thermal voltage to the output voltage and to output the same. A reference voltage generation circuit of such a configuration enables a circuit outputting a reference voltage with little fluctuation due to temperature to be constructed on an LSI.
Non-patent Document 1: T. MATSUDA, R. MINAMI, A. KANAMORI, H. IWATA, T. OHZONE, S. YAMAMOTO, T. IHARA, S. NAKAJIMA, “A Temperature and Supply Voltage Independent CMOS Voltage Reference Circuit”, MICE TRANS. ELECTRON., Vol. E88-C, No. 5, pp. 1087-1093, May 2005.